Family We Choose
by Taisi
Summary: Casey's learned the hard way that when you fight with physics you always lose, but those hands around his wrists are unbreakable, and Mike's voice is almost breezy; like whatever's about to happen is all part of the plan, like everything's gonna be just fine. (2k12, twoshot.)
1. Chapter 1

Casey's a lot of things, but he _ain't _stupid. And the turtles aren't exactly hard to figure out.

Leo's the boss. Donny's the genius. Raph's the brute force. Mikey's the wild card.

You don't argue Leo's lead if you're hoping to have any of his brothers' support; you don't put down Donny's techno mumbo-jumbo if you don't want him to make you look like an idiot in three seconds or less; you _don't _goad Raph into a fight unless you're really lookin' for some new bruises and a few loose teeth; and you don't try to predict Mike, ever.

But underneath all that- under the masks and the secret, vigilante ninja stuff- they're kids, and Casey's age, with quirks and pet peeves and favorite episodes of stupid daytime T.V. shows, and they're _brothers. _They fight like assholes and they play dirty and they get on each other's last nerve as often as they can, and any given second of any given day they would _die _for each other, and that's a knowledge they carry quietly, like it's nothing special_._

Casey picked it up after knowing them less than a _week_. There's _protective, _then there's the _Hamatos. _And if he was gonna hang with Raph, if he was gonna have _anything _to do with him or his brothers or their late night vigilante show, then he had to get behind those unspoken family rules a hundred and ten percent.

Which is why he's in the position that he's in now, meeting that skeletal werewolf-looking dude glare for glare, ignoring the razor claws and teeth and shifting another step or two to cover Mike, who landed too hard when the wolf creep threw him and hasn't found his feet yet.

Mike's his best friend's baby brother. That kinda puts the kid on a bit of a pedestal as far as Casey's concerned. Granted, he's made of the same tough stuff his brothers are, and he could hand Casey his butt on a silver platter about as easily as they could- and he's always _everywhere, _loud and larger than life and a walking antonym for the word 'ninja', it usually makes more sense to push him into a puddle than it does to _baby _him or handle him with little kid gloves-

But at the end of the day, it goes without saying. It's something Raph's never explained to him, something Leo and Don have never said out loud, it's just... _obvious. _Casey's got a little sister at home- he gets it.

"You okay?"

Casey calls the question over his shoulder, 'cause he's not taking his eyes off Rahzar for a second. He can hear Mikey pulling himself to his feet. Even though it doesn't take long by normal-person standards, ninja standards are _worlds _different, and worry's taking front seat in Casey's brain at this point cause the kid hasn't even answered him yet.

"Hey, Mike, you with me?"

"Yyyeah," the turtle finally replies, drawing the answer out slowly like he isn't entirely sure it's the right one. "Yeah, I'm okay." There's a rattle of chains, and Mike moves up to Casey's side.

The others are fighting that fish guy and about three dozen of those stupid robo-ninjas, out of sight but close enough Casey can hear them clearly. They're like ten stories under Manhattan, whole miles from the lair, and Casey can't even remember how they got ambushed, just that Don had some bright idea about maps and security systems, and his brothers- and Casey- got caught up in his enthusiasm and tagged along. The light tower Don rigged is the only source of light in the underground, since the turtles ditched their flashlights and electric lamps the second a fight was on. Casey's gotta stick by the tower, and it's the biggest disadvantage in a ninja fight that he can think of. Mikey must be on the same page, because he stands by Casey's side instead of capering off to join his brothers, and he searches the dark with narrow eyes.

"Somethin' feels weird," he says at length, and Casey tightens his grip on his baseball bat. Those words outta Mike's mouth never bode well. "Dude, I think we should- "

With a guttural roar, Rahzar's practically on top them out of thin air, and Casey goes down, hard. The concrete scrapes roughly against his mask, and he tries not to swear. The hand that shoved him is still pressed to his back, three-fingered and next to human and distinctly unclawed. "What _gives, _man?" Mike doesn't have an answer, just pushes him down a little harder and talks over his head.

"Rad-Brad got an upgrade! Since when are you packin' heat, dude?"

"Oh, don't worry, little turtle. They're only tranquilizers. My master wants you _alive_."

Mike whistles. "That's pretty generous. Maybe he's not such a bad guy after all."

Now that Casey's gotten pretty personal with the ground, he's startled and dismayed to find it's not very... stable. "Uh, Mike- "

He's cut off as he's rolled to one side, none too gently, and Mike's nunchucks are a blur Casey doesn't even need to see. The tranq gun discharges once, twice, three times, but Casey doesn't feel the sting of a needle anywhere- he _does _feel the concrete under his hands start to shift with the weight Rahzar's throwing around, and his heart jumps to his throat. In about two seconds, they are _so screwed_.

Pounding feet in the tunnel behind them, and Raph's yelling their names. "He's got tranqs," Casey shouts back before anything else, and he sees his friend's eyes narrow, two bright pinpricks of poison green. They get trained for this kind of thing back home, with toy arrows and blindfolds, and Raph doesn't slow down for a second. Behind him, in the glare of the floodlight, Casey can just make out Donny and Leo behind him, rushing over, and Casey has a second to think_ Okay maybe this will be okay _and then-

gravity_._

He's falling through the crappy floor as it rips open under him like paper- and he's panicking a little as he scrabbles for a handhold that isn't crumbling concrete. They're underground already, where _else _is there to fall?

The light topples over, the fluorescent bulbs popping like gunshots, and his friends are shouting at the same time. Oh, god, Casey hopes they're on solid ground. And Mike! Mike was right next to him, where is-

"Gotcha," the kid says, and two hands wrap around Casey's wrists. It won't somehow save him- too late in the game for that, Casey's learned that when you fight with physics you always lose- but those hands are strong and unbreakable anyway, and Mike's voice is almost breezy; like whatever's about to happen is all part of the plan, like everything's gonna be just fine.

And when Casey falls, his best friend's baby brother falls with him.


	2. Chapter 2

It's pitch black down here. Before he even opens his eyes he can feel it, the darkness pressing against him like something physical- and on top of that, there's something _actually _physical on top of him, pinning him down. And in that tiny space between newly conscious and actually aware, cool panic slips through the cracks of learned courage and Casey's heart kicks up a notch.

_Claustrophobic, _Donny had said once, voice gentle and just for the two of them. Casey had scowled but he hadn't denied it, because, _yeah. _Hell yeah. And now- right now, it's _dark._ There's no light reaching in from cracks or corners, nothing to hint at how much room there is- or how much room there isn't- and he's maybe a little bit starting to freak out because he can't even move his arms.

But then the rest of his senses come online, the rational side of his brain sprinting to save him before he can make a total idiot out of himself, and he recognizes one of those distant ambient sounds of the dark underground as someone _humming._

Oh, yeah. Casey didn't fall alone.

"Mike?"

Instantly the humming stops and the weight on him shifts, easing up a little and giving him more of a personal bubble.

"Hey, dude! You finally with me?"

God knows what happened or where they are, but Mike's voice is enough to clear Casey's head completely.

"Looks like it. How long was I out?"

"Not long. You missed the rock parade."

Large, blunt fingers are moving along Casey's arm up to his shoulder. They find his face, and feel around to the back of his head, and it takes Casey a minute to figure out why.

Once he gets it he grumbles, and swats Mike away with a newly freed arm. "Knock it off, I'm fine. I've had worse than a couple knocks on the head, believe me. What rock parade?"

The kid's giggling as he leans back. He's Raph's baby brother, but he's Casey's buddy, too. They have a secret handshake and a few inside jokes no one else understands, and in the darkness that makes them both blind, Mike's relief stands between them as stark and obvious as a neon sign. He's glad Casey's okay.

"The rocks that followed us down. Lucky thing I have a shell, 'cause they would have flattened you, bro. I didn't wanna move till you woke up, in case even more fell down."

Casey shoves his mask to the top of his head- his entire body _aches_, his eyes hurt from trying to adjust to the absolute darkness- but suddenly the pain and the dark are the last things on his mind, and he stares at the spot where he thinks Mikey's face would be.

He doesn't know a ton about turtles, which seems kinda dumb since he trusts his life to a few of them practically every other night, but to be fair he doesn't know a lot about people, either. But Casey plays a contact sport, and beats up criminals with bats and hockey sticks; he _does _know a little about bones, and especially how to break them. He knows damage to the spine is a major no- go. And he also knows- from listening to Don patch up his brothers all those times, lecturing angrily and fearfully as he smeared plaster across cracks in their carapaces with unending care- that their shells are _infused with their spines. _

He reaches out blindly to sock Mike square in the shoulder. A startled yelp echoes around them and Casey snaps, "You're an idiot! What if you got yourself hurt, huh? Next time, just drag me out of the way by my ankles if you have to!"

He doesn't need to see to know there's a wounded pout on Mike's face, 'cause he can hear the turtle's mutter just fine. And maybe it's not fair to yell at him- he's only down there in the first place because of Casey, and he only did the same thing his brothers would have done. And it sounds like he's moving fine, there isn't any underlying tension in the way he's talking, but Casey won't know for sure the kid's okay until he can _see _him_. _

"You got a light in that belt of yours?" Casey asks abruptly. "I can't see jack, dude."

"Um... I thiiink I lost my penlight somewhere... man, Donny's gonna be so mad... Oh! Here, you can use my T-Phone."

The shell-shaped cell is pressed into Casey's hand, and he's familiar enough with the battered thing that it's practically muscle-memory to unlock it with a swipe of his thumb. The glow is a hundred times brighter than usual in the dark of the underground, and Casey has to squint through the sudden light as he turns the screen towards Mike. Mike doesn't flinch the way Casey did, watching curiously through the narrowed whites of his eyes.

"What're you doing?"

"Shut up."

The cheerful orange of Mike's ninja mask is stained dark on one side- Casey lunges closer, horrified- but the cut is shallow, not even bleeding anymore, and instant relief steals all the air away.

And the kid starts laughing, nudging him away with a friendly shoulder.

"I'm okay! Jeez, brothers are all the same."

Casey shoves him back gruffly; can't help the edges of a smile as it forms on his face.

The T-Phone chooses that moment to go off. The ringer is silenced but it vibrates in Casey's hand, and Mike snatches it away a second later. He answers the incoming call with a gleeful, "Raph? Dude! You guys okay? Yeah, yeah- yeah, we're okay. I think we fell down into a storm sewer. I haven't really tried to look around yet. Should we try to find a way up?" Mike's grin is bright even in the dark, tapping his fingers as he listens to whatever Raph's saying, and after a moment he laughs. "Gotcha! Okay. Sure, here he is."

Casey's not really surprised when the phone gets handed over to him. He puts it to his ear and says, "Hey, Raph."

_"Hey, Jones." _Raphael's voice alone is enough to make Casey wince; the guy's obviously been freaking out up until this point, and the forced calm would be obvious to anyone who knows him. _"Don's tracking Mikey's T-Phone, and he's already mapped a way down to you guys. We're on our way. You good?"_

The turtles know about his phobia, they just never mention it. Casey smiles a little in the dark even though what he says is, "I'm _fine_, you dork. Man, feels like I'm talking to Leo."

_"Shut up. And Mikey- Mikey's okay? He said he was, but- "_

"He's okay. A little banged up, but yeah." Next to him, Mike rolls his eyes.

_"Okay. Good. He didn't do anything stupid down there, did he?"_

"Well, let's see," Casey says, slowly. "I guess it depends on how you look at it. Like, on one hand, practically jumping into a black pit and taking a ton of falling rocks on his back just to protect me sounds majorly stupid, yeah." Mike gapes at him while Raph splutters something incoherent on the other end of the line, and Casey grins at them both.

On the other hand, Mike really saved Casey's ass- the same way he saves complete strangers all the time from thugs and low-lives- and there's nothing stupid about that. But Casey figures the guys already know that much. They sound pissed off now, as Leo's voice erupts from the speakerphone in the lecture of a lifetime, but they'll be proud of him, too, once they have him back safe and sound.

"You got me in trouble. You suck," Mike mumbles a few minutes later as he hangs up, and Casey barks out a laugh and slings an arm around Mike's shoulders, tugging him closer.

"Any time, little brother," he says. The kid's head fits against his shoulder almost perfectly, the same way his sister's used to; and when the young ninja innocently suggests a game of_ I Spy _to pass the time, Casey grins and settles in with him to wait for the rest of their family in the dark.


End file.
